For a practical micro-nano device, it not only needs manufacture of a high-precision micro-nanostructure with a key function but also manufacture of a large-area macrostructure capable of being connected with an external input/output signal. Co-existance of multi-scale structures cannot be avoided in a micro-nano device manufacturing process. For example, in a typical fin field effect transistor structure, the size of a source and a drain connected with an external electrode is about greater than 100 μm*100 μm, but the characteristic size of a fin structure connected between the source and the drain is about 20 nm*100 nm, i.e., a ratio of the large-area source and drain structures with a micron-scale precision to the fin structure with a nano-scale precision is 5000000:1. For another example, in a structure of a photonic crystaldemultiplexer, the area of a light incidence waveguide/emergence waveguide with a micron-scale precision is about 198000 μm2, but the area of a high-precision structure with a nano-scale precision is 4500 μm2, and a ratio of the incidence waveguide/emergence waveguide area to the area of the high-precision structure is 44:1.
At present, a micro-nano structure or device containing multi-scale structures is usually manufactured sequentially by adopting various methods in turn. For example, ultraviolet mask photolithography is adopted for manufacturing a large-area micro-scale-precision structure, and then photolithography such as electron beam photolithography is adopted for manufacturing a nano-scale structure. When exposure is performed sequentially by adopting these various methods, an alignment mark needs to be made on a substrate material, and an optical system needs be used for observing splicing in an overlay process of structures manufactured by adopting different methods. Further, the splicing precision is further restricted by imaging resolution of the observation system. Additionally, a masking plate needs be manufactured through electron beam photolithography point-by-point scanning for each designed structure. Hence the period of the device manufacturing process is long, the technology is complex and the cost is high. When a single high-precision processing technique (such as an electron beam point-by-point scanning) is used for manufacturing, the manufacturing time will be very long and the efficiency is lower.
Maskless photolithography techniques based on plane projection exposure of a spatial light modulator (such as DMD plane projection photolithography) are suitable for manufacturing a submicron-scale precision two-dimensional or three-dimensional large-area complex structure, and laser direct writing techniques (such as a femto-second laser two-photon fabrication technique) are suitable for fabricating small-area nano-scale two-dimensional or real three-dimensional structures. These two techniques both are realized by directly processing graphic data and controlling the movement of a mobile station or the deflection of a DMD micro-mirror through a computer according to a data document. Since these two methods both use photon beam processing and spatial environment requirements for realizing them are the same, the two methods can be integrated and used for realizing one-step formation of cross-scale complex structures. Up to now, there have been no systems or methods for realizing cross-scale structure processing by combining these two techniques.